Dowel hole locator



Dec. 25, 1951 W. M. GARRARD DOWEL HOLE LOCATOR Filed Dec. 6, 1950 FIG 2 3s as- 39 INVENTOR. F I 3 WALTER M. GARRARD ATTORNEY Patented Dec. 25, 1951 UNITED STATES PATENT OFFICE 2,579,564 DOWEL HOLE LOCATOR Walter Garrard, Atlanta, Ga. Application December 6, 1950, Serial No. 199,421

11 Claims. 1

without further planing or excessive sanding.

Many former methods have been so inaccurate that much time and labor is consumed to finally finish the piece smooth. Quite often this extra planing and sanding changes the final dimensions of the several pieces to such an extent that mass production and assembly is impossible and each item must be completed by hand.

It is an object ofthe present invention to pro vide a dowel hole positioner which is simple in its construction and operation, easy to manufacture and which may be used with any conventional drill press, whether of the bench type or floor model.

Another object of the invention is to provide such a device which may be used with any diameter drill bit which automatically. spaces one or several dowel holes asdesired and at exact increments so that when a mating piece of lumber is similarly drilled the two will fit exactly without further planing or sanding.

A further object of the invention is to provide a dowel positioner which provides mechanisms for spacing dowels in matching pieces of wood in any desired increments of an inch and wherein the same may be used for both straight lumber as well as pieces having an odd shape or contour normally requiring special jigs and fixtures for doweling.

A further object of the invention is to provide such a mechanism which may be temporarily clamped without the use of special tools to the conventional drill press for use as a dowel positioner, and which in no way hinders the press for subsequent normal use.

Further objects and advantages of the invention will become apparent in the course of the following detailed description when viewed together with the accompanying drawing in which:

Fig. 1 is a top or plan view of an embodiment of my invention in a dowel hole positioner.

Fig. 2 is a front view thereof.

Fig. 3 is a cross-sectional view taken along line 3--3 in Fig. 1.,

Fig. 4 is an enlarged, crosssectional view taken along line 4-4 in Fig. 1.

In the drawing, numeral I0 designates a base member which, in the present instance, is made of a rectangular piece of hard wood, but which may also be made of some light metal casting or other material.

As seen in the top view of Fig. 1, I have provided right and left hand adjusting plates designated generally by the numerals I I and 12 respectively. Each of the plates is made of relatively thin sheetmetal and arranged to slide longitudinally along the base member ill by means of the positioning studs l3 and elongated slots [4 therefor. It will be noted that the forward edge of each plate extends out over the front edge of the base member Ill and each of these extending edges is provided with equally spaced slots 15. In the present instance the slots are equally spaced in increments of /2 inch, but may be spaced any distance apart as desired.

The left hand plate I2 is provided with an extension I 6 on the inner edge of which I have cut a rack l1 enmeshed with a pinion 18. The right hand plate H is also provided with a rack 19 formed on its inner edge and also enmeshed with the pinion 13. It is readily apparent, now, that if the pinion is rotated counterclockwise, both plates will be made to slide upon the base member Ill in a direction away from each other, and if the pinion is rotated clockwise, the plates II and I2 will be drawn toward each other until their inner ends finally butt together. The pinion I8 is rotatably mounted upon a stud 20 set into the base member ill and is provided with a positioning arm 2| spot-welded or otherwise afiixed thereto.

In Fig. 1 it can be seen that I have provided a segment 22 held to the base member 10 by means of screws 23. The segment 22 is provided with radial calibrations 24 preferably in increments of A; or an inch so that when the side edge of the positioning arm 2| is placed in alignment with one of the calibrations, the two plates II and i2 will be moved oppositely this same distance from a center line or from the point of their abutting ends. For instance, if the positioning arm 21 is set in alignment with the first calibration of one-eighth inch, the two inner ends of the movable plates II and 12 would be oneeighth of an inch from a center line, or a total of one-quarter of an inch from each other. Any setting of the positioning arm 2| on the calibrated segment 22 places the ends of the two plates twice that distance apart.

To lock the positioning arm at any desired arcuate movement along the segment 22 I have provided holes 25 in the segment 22 adapted to slidably receive a locking pin 26. The holes 25 are so positioned that when engaged by the pin 26, the outer side edge of the positioning arm 2| is contiguous with the radial calibration 24 on the segment 22 and the two plates II and I2 are accurately spaced.

While any other method may be used to support thelocking pin 26, I have shown in Fig. 4 a construction suitable for this purpose. At the outer end of the positioning arm 2| I have welded an inverted cup 21 to the positioning arm 2|. In the hollow of the cup I have placed a compression spring 28, the upper end of which rests against the cup bottom and the bottom end rests against a washer 29 which is affixed to the pin 26; so that when the pin 26 "is lifted by the head 30, the spring 28 is compressed to keep the pin 26 positioned in its selected hole.

At each end of the bas member I have provided standards 3| and '32 affixed to the base member I by means of screws. These standards are arranged for supporting a rod 34 parallel to the top face of the base member ID. Slidably mounted upon this rod 34 I have provided an arm 35 bent in the manner shown in Fig. 3. The thickness of the arm 35 is such that it may be slidably received by any of the slots l formed on the forward edge of either of the two plates II or i2. For example, the stop head 36 may be set at one-half inch increments along the left hand plate l2 by lifting the arm 35 from one slot, moving it along the rod 34, and placing it in another slot. The same operation may be performed with the other plate l2.

It will be noted that the slots |5 of each plate H and I2 are numbered, beginning from the inner abutting edges, outwardly. In the present instance, there are 12 slots, so numbered, upon each plate. When the stop head 36 is being used in connection with the first slot of either plate, its inside face will be flush with the inner end of that plate and may be moved outwardly in onehalf inch increments, or for a total of 5 inches. It is to be understood here that the number of slots is immaterial and may be made to suit any particular operation.

Upon the inner end of the left hand plate I2 I have provided calibrations 3! from zero through three-quarters of an inch in increments of oneeighth inch. The zero position, of course, is flush with the front face of the base member, with the other calibrations extending outwardly therefrom. For examplaif it is desired to drill a dowel hole in the center of a board threequarters of an inch thick, the board would be held u against the forward face of the base member and the point of the drill set to the three-eighth inch mark on the calibration 31.

To further assist in setting the point of the drill at various distances from the side edge of a board of any given thickness, I have provided a gaging strip 38 provided with a pin 39 on the back side thereof adapted to be slidably received in a hole 40 on the front face of the base member It). Any odd settings not accounted for on the calibrations 3'! may be made by this gaging strip 38 together with the use of shims 4| which may be placed behind the gaging strip 38 to give the proper setting. The primary use, however, of the gaging strip is for offset drilling. For instance, if a chair rail is to be doweled to a pair of stiles with a definite oifset, the amount of this offset may be made by drilling the rail in. the

, a 4 usual manner and by applying the gaging plate 38 to ofiset the drilling of the stiles.

The following examples of use of my device will show more clearly its versatility-and the accuracy obtained in placing dowel holes in pieces of lumber.

Let it be assumed that the device is being used in connection with a bench model drill press which is mounted upona table or suitable work bench. The base table of the press must be turned side" ways approximately degrees so that the spindle of the press may be swung around to clear the edge of the bench. ,The base member, 10 of my device is clamped rigidly to the upper table of the drill press andso positioned that the boards to be drilled may be held against its front face without touching the bench,

or table. With the device thus clamped and ready for use, let it be assumed that it is required to place two dowel holes in the side edges of a board. The dowel holes are to be onefourth inchin diameter, one inch deep, the first hole being one-half inch from the end of the board and the other dowel hole exactly two inches from the first hole. Both holes are to be exactly in the center of the board which is threefourths inch thick.

With this information given, an operator closes the two plates II and I2 by moving the positioning arm 2| clockwise to the zero position. By manipulation of the spindle arm, the operator brings thepoint of acne-fourth inch drill to the three-ei'ghths inch mark on the thicknesscalibrations 31 and locks both the spindle arm and the drillin'this position. The exact center of the three-fourths inch board is thus found. Since the first dowel hole is to be one-half inch from the board end, the operator then sets the positioning arm 2| to the one-half inch calibretion on the segment 22, thus moving each plate, by means of the above described gear action, exactly one-half inch away from the point of the previously set drill point.

It has already been pointed out that, with the arm 35 inthe No. slot of either plate, the stop head 36 is heldflush' with the plate ends. Therefore, the operator places his board up against the front face of thebase member ID and moves the board end into engagement with the stop head 36, and the first hole is automatically positioned. By setting the depth gage on the drill press to one inch, the operator may then drill the first required hole. Since the second hole is required to be two inches away from the first hole, the operator re-sets the arm 35 in the No. 5 slot which is four halves, or two inches, away from the first hole. With this new setting of the stop head 36, the second hole is drilled to the required depth.

It will be remembered that the segment 22 is calibrated in increments of one-eighth inch, while theplates II and I2 are in increments of one-half inch. However, with the device as shown, the two setting mechanisms are so coordinated that the stop head 36 may actually be set in increments of one-eighth inch. For example, let it be requiredto position a dowel hole in the board mentioned in the previous example exactly three and five-eighths inches from the board end. In this instance, the five-eighths inch setting would be made by moving the positioning arm 2| to the five-eighths inch calibration on the segment 22,

and the stophead placed in the No. 1 slot, which.

From the above examples of use of the device. it is readily seen that the movable stop head 36 may be used in connection with the slots 15 of either of the plates I I or I2, since the plates are moved simultaneously and equi-distantly in opposite directions from the setting of the drill point. Such an arrangement is highly advantageous when working in close quarters or where an operator finds it more convenient to place his work upon one side or the other. Also, certain pieces of furniture intended for matching must be drilled oppositely, and such opposite spacing is easily and accurately maintained.

As explained above, if the calibrations for thickness of the boards are not suitable, use may be made of the gaging plate 38 and suitable shims.

The above examples have been given to illustrate the matching of boards along their side edges to produce a final doweled joint which is flush and smooth. It will be understood that the ends of two boards could be matched in the same manner and by following the same steps of operations.

Occasionally it is required to position dowel holes in the center of strips of considerable length. such as joining a chair rail to a stile. Since the stile is considerably longer than the entire device, it is quite obvious that the stop head 36 cannot be used, and must therefore be pivoted over and around its supporting rod 34 where it is out of the way. The width of the rail is then located on the stile by measurement and by marking with a pencil and square. Let it be supposed that the rail is one and one-half inches wide and two dowel holes are required; one hole one-half inch from the bottom marking of the rail and the other one-half inch from the top marking of the rail. Again the positioning arm 2| is moved through its are upon the segment 22 until the spacing or one-half inch is reached. This means that the two inner ends of the two plates H and I2 are one-half inch from the center line or from the drill point. Using one of the markings of the rail upon the stile, this mark is held in alignment with an edge of one of the plates and the hole is drilled. The other marking, representing the other side of the rail is held in alignment with the other of the plates which positions the drill point exactly one-half inch from the drill point, and this hole is ready for drilling. If the hole spacing is beyond the range of the calibrated segment 22, the markings may be made to align with a side of the several slots and thus grouped to total the desired number of inches and fractions thereof. In this manner, the slots are used together with the fractional setting of the positioning arm 22 to give measurements of close increments. An alternative methodgof drilling extra long pieces would be to spot a small nail in the piece as a bench mark and use the nail to hold against the proper slots in either of the two plates H or l2 to give the right spacing between the dowel holes.

Odd shaped pieces and pieces having an irregular contour may be advantageously spotted" with the present invention to insure exact alignment for doweling. For example, a semi-circular piece of wood such as a table top or the like may be advantageously and accurately drilled for I doweling a given distance from its circumferential edge in the manner described above.

.It is understood that the above described device cannot be suitably used in all cases, but will satisfy most of the requirements in constructing chairs. cabinets, tables and the like where doweled joints are most frequently used. In many cases the position of the dowel hole may be advantageously spotted or located by the device and the actual drilling finished by hand. Moreover, the device may be used with a mortising attachment or with router bits to form recesses which must be accurately positioned in a piece of wood.

The device is simple in its construction and may be used by any novice to make perfect fitting joints. Inaccuracies of measurement by inexperienced workmen are eliminated by outlining a given pattern for theplacing of dowel holes. Since all measurements are done by mechanical movements, a re-checking for accuracy is unnecessary.

As mentioned above. the device may be made to any size with any suitable increments in calibrating. Other changes in the actual construetion may be made without departing from the scope of the invention as defined by the following claims.

I claim:

1. Apparatus of the class described comprising, a base member, a plate adjustably mounted on said base member, said plate having an extending edge overhanging an edge of said base member, said extending edge being provided with a pin.- rality of spaced slots, means for adjusting the position of said plate on said base member, an arm movably mounted upon said base member for selective reception within said spaced slots, and a stop head carried by said arm, said stop head having a face in alignment with the inner end of said plate when said arm is received in the first of said slots in said plate.

2. Apparatus of the class described comprising, a base member, a pair of plates adjustably mounted on said base member, each of said plates having an extending edge overhanging an edge of said base member, each said extending edge being provided withra plurality of spaced slots, means for adjusting the position of said plates on said base member, an arm movably mounted upon said base member for selective reception within said spaced slots, and a stop head carried by said arm, said stop head having a face in alignment with the inner end of one of said plates when said arm is received in the first of said slots in that plate.

3. Apparatus of the class described comprising, a base member, a pair of plates adjustably mounted on said base member, each of said plates having an extending edge overhanging an edge of said base member, each said extending edge being provided with a plurality of spaced slots, means for adjusting the position of said plates on said base member, an arm movably mounted upon said base member for selective reception within said spaced slots, and a stop head carried by said arm, said stop head having a face in alignment with the inner end of one of said plates when said arm is received in the first of said slots in that plate, said stop head also having an opposite face in alignment with the inner end of the other of said plates when said arm is received in the first of said slots in that plate.

4. Apparatus 0f the class described comprising, a base member, a pair of plates adjustably mounted on said base member, each of said plates having an extending edge overhanging an edge of said base member, each said extending edge being provided with a plurality of spaced slots, means for adjusting the position of said plates on said base member, an arm movably mounted upon said base memberfor selective reception within said spaced slots, a stop head carried by said arm, said stop head having a face in alignment with the inner end of one of said plates when said arm is received in the first of said slots in that plate, saidstophead also having an opposite face in alignment with the inner end of the other of said plates when said arm is received in the first of said slots in that plate, and a gaging strip adjustably positioned on said base member beneath the extending edge of said adjusting plate.

5. Apparatus of the class described comprising, a base member, a pair of plates adjustably mounted on said base member, each of said plates having an extending edge overhanging an edge of said base member, each said extending edge being provided with a plurality of spaced slots, means for adjusting the position of said plates on said base member, a rod mounted upon said base member, an arm mounted upon said rod for selective reception within said spaced slots, a stop head carried by said arm, said stop head having a face in alignment with the inner end of one of said plates when said arm is received in the first of said slots in that plate, said stop head also having an opposite face in alignment with the inner end of the other of said plates when said arm is received in the first of said slots in that plate, and a gaging strip adjustably positioned on said base member beneath the extending edge of said adjusting plates.

6. Apparatus of the class described comprising, a base member, a pair of adjusting plates slidably mounted on said base member, each of said plates having an extending edge overhanging an edge 'of said base member, each said extending edge being provided with a plurality of equally spaced slots, means for adjusting the position of said adjusting plates on said base member, means for retaining said adjusting plates in adjusted position, a rod mounted upon said base member, an arm slidably and swingably mounted upon said rod for selective reception within said equally spaced slots, and a stop head carried by said arm, said stop head having a face in alignment with the inner end of one of said plates when said arm is received in the first of said slots in that plate.

7. Apparatus of the class described comprising, a base member, a pair of adjusting plates slidably mounted on said base member, each of said plates having an extending edge overhanging an edge of said base member, each said extending edge being provided with a plurality of equally spaced slots, means for adjusting the position of said adjusting plates on said base member, means for retaining said adjusting plates in adjusted position, a rod mounted upon said base member, an arm slidably and swingablymounted upon said rod for selective reception within said equally spaced slots, a stop head carried by said arm, said stop head having a face in. alignment with the inner end of one of said plates when said arm is received in the first of said slots in that plates, said stop head also having an opposite face in alignment with the inner end of the other of said plates when said arm is received in the first of said slots in that plate, and a gaging strip ad- .iustably positioned on said base member beneath the extending'edge of said adjusting plates.

8. Apparatus of the class described comprising, a base member, a pair of adjusting plates slidably mounted on said base member, each of said plates'having an extending edge overhanging an edge of'said base member, each said extending edge being provided with a plurality of equally spaced slots, means for slidably adjusting. the po-- sition of said adjusting plates on said base memher, said means including releasable means for retaining said adjusting plates in adjusted position, a rod mounted upon said base member, an arm slidably and swingably mounted upon said rod for selective reception within said equally spaced slots, and a stop head carried by said arm, said stop head having a face in alignment with the inner end of one of said plates when;

said arm is received in the first of said slotsin that plate, said stop head also having an opposite face in alignment with the inner end of the other of said plates when said arm is received in the first of said slots in that plate.

9. Apparatus of the class described comprising; a base member, a pair of adjusting plates slidably mounted on said base member, each of said plates having an extending edge overhanging an edge of said base member, each said extending edge being provided with a plurality of equally spaced slots, each of said plates also having another edge provided with a rack, arotatably mounted pinion engaging each said rack in such manner that rotation of said pinion in one direction will slide said adjusting plates toward each other and rotation of said pinion in the opposite direction will slide said adjusting plates apart, means for rotating said pinion to adjust said adjusting plates, means for retaining said adjusting plates in adjusted position, a road mounted upon said base member, an arm slidably and swingably mounted upon said rod for selective reception within said equally spaced slots, and a stop head carried by said arm, said stop head having a face in alignment with the inner end of one of said plates when said arm is received in the first of said slots in that plate, said stop head also having an opposite face in alignment with the inner end of the other of said plates when said arm is received in the first of said slots in that plate.

10. Apparatus of the class described compris ing, a base member, a pair of adjusting plates slidably mounted on said base member, each of said plates having an extending edge overhanging an edge of said base member, each said extending edge being provided with a plurality of equally spaced slots, each of said plates also having another edge provided with a rack, a rotatably mounted pinion engaging each said rack in such manner that rotation of said pinion in one direction will slide said adjusting plates toward each other and rotation of said pinion in the opposite direction will slide said adjusting plates apart, means for rotating said pinion to adjust said adjusting plates, means for retaining said adjusting plates in adjusted position, a rod mounted upon said base member, an arm slidably and swingably mounted upon said rod for selective reception within said equally spaced slots, a stop head carried by said arm, said stop head having a face in alignment with the inner end of one of said plates when said arm is received in the first of said slots in that plate, said stop head also having an opposite face in alignment with the inner end of the other of said plates when said arm is received in the first of said slots in that plate, and a gaging strip adjustably positioned on said base member beneath the extend ing edge of said adjusting plates.

11..Apparatus of the class described-comprising, a base member, a pair of adjusting plates slidably mounted on said base member, each of said plates having an extending edge overhanging an edge of said base member, each said extending edge being provided with a plurality of equally spaced slots, each of said plates also having another edge provided with a rack, a rotatably mounted pinion engaging each said rack in such manner that rotation of said pinion in one direction will slide said adjusting plates toward each other and rotation of said pinion in the opposite direction will slide said adjusting plates apart, means for rotating said pinion to adjust said adjusting plates, said means including releasable means for retaining said adjusting plates in adjusted position, a rod mount- 10 ed upon said base member, an arm slidably and swingably mounted upon said rod for selective reception within said equally spaced slots, a stop head carried by said arm, said stop head having a face in alignment with the inner end of one of said plates when said arm is received in the first of said slots in that plate, said stop head also having an opposite face in alignment with the inner end of the other of said plates when said arm is received in the first of said slots in that plate, and a gaging strip adjustably positioned on said base member beneath. the extending edge of said adjusting plates.

WALTER M. GARRARD.

No references cited. 

